Thousands of luminous sheets and barbed tongues of fire were cast in various directions. Some, extending beyond the dome of smoke, dissipated it, leaving behind an incandescent powder. This was accompanied by successive explosions, resembling the discharge of a battery of machine-guns.

Cyrus Harding, the reporter, and Herbert, after spending an hour on the plateau of Prospect Heights, again descended to the beach, and returned to Granite House. The engineer was thoughtful and preoccupied, so much so, indeed, that Gideon Spilett inquired if he apprehended any immediate danger, of which the eruption might directly or indirectly be the cause.

"Yes, and no," answered Cyrus Harding.

"Nevertheless," continued the reporter, "would not the greatest misfortune which could happen to us be an earthquake which would overturn the island? Now, I do not suppose that this is to be feared, since the vapors and lava have found a free outlet."

"True," replied Cyrus Harding, "and I do not fear an earthquake in the sense in which the term is commonly applied to convulsions of the soil provoked by the expansion of subterranean gases. But other causes may produce great disasters."

"How so, my dear Cyrus?'

"I am not certain. I must consider. I must visit the mountain. In a few days I shall learn more on this point."

Gideon Spilett said no more, and soon, in spite of the explosions of the volcano, whose intensity increased, and which were repeated by the echoes of the island, the inhabitants of Granite House were sleeping soundly.

Three days passed by--the 4th, 5th, and 6th of January. The construction of the vessel was diligently continued, and without offering further explanations the engineer pushed forward the work with all his energy. Mount Franklin was now hooded by a somber cloud of sinister aspect, and, amid the flames, vomiting forth incandescent rocks, some of which fell back into the crater itself. This caused Pencroft, who would only look at the matter in the light of a joke, to exclaim,--

"Ah! the giant is playing at cup and ball; he is a conjurer."

In fact, the substances thrown up fell back again in to the abyss, and it did not seem that the lava, though swollen by the internal pressure, had yet risen to the orifice of the crater. At any rate, the opening on the northeast, which was partly visible, poured out no torrent upon the northern slope of the mountain.

Nevertheless, however pressing was the construction of the vessel, other duties demanded the presence of the colonists on various portions of the island. Before everything it was necessary to go to the corral, where the flocks of musmons and goats were enclosed, and replenish the provision of forage for those animals. It was accordingly arranged that Ayrton should proceed thither the next day, the 7th of January; and as he was sufficient for the task, to which he was accustomed, Pencroft and the rest were somewhat surprised on hearing the engineer say to Ayrton--

"As you are going to-morrow to the corral I will accompany you."

"But, Captain Harding," exclaimed the sailor, "our working days will not be many, and if you go also we shall be two pair of hands short!"

"We shall return to-morrow," replied Cyrus Harding, "but it is necessary that I should go to the corral. I must learn how the eruption is progressing."

"The eruption! always the eruption!" answered Pencroft, with an air of discontent. "An important thing, truly, this eruption! I trouble myself very little about it."

Whatever might be the sailor's opinion, the expedition projected by the engineer was settled for the next day. Herbert wished to accompany Cyrus Harding, but he would not vex Pencroft by his absence.

The next day, at dawn, Cyrus Harding and Ayrton, mounting the cart drawn by two onagers, took the road to the corral and set off at a round trot.

Above the forest were passing large clouds, to which the crater of Mount Franklin incessantly added fuliginous matter. These clouds, which rolled heavily in the air, were evidently composed of heterogeneous substances.